Note: Descriptions are shown in the official language in which they were submitted.
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
1
PRINTED SECURITY FEATURE, OBJECT COMPRISING SUCH A PRINTED
SECURITY FEATURE, AND PROCESS OF PRODUCING THE SAME
TECHNICAL FIELD
The present invention generally relates to a printed security feature
provided onto a printable substrate, which printed security feature includes a
printed area consisting of a multiplicity of adjacent rectilinear and/or
curvilinear
elements printed with a given spatial frequency.
BACKGROUND OF THE INVENTION
European Patent Publications Nos. EP 0 710 574 A2 and
EP 1 291 195 Al each disclose such printed security features.
Further improvements of these known printed security features are
required in order to make forgery by counterfeiters even more difficult.
SUMMARY OF THE INVENTION
A general aim of the invention is therefore to improve the known printed
security features.
More specifically, an aim of the present invention is to provide such a
printed security feature that is both difficult to counterfeit and requires
high-
precision printing equipment for it to be produced in an adequate manner.
Still another aim of the invention is to provide such a solution which
enables the creation of a simple and readily understandable optical effect
when
illuminated by means of non-visible light, such as ultraviolet light, and
which
requires simple tools (such as suitable UV light) in order to control the
genuineness of the security feature.
These aims are achieved thanks to a printed security feature defined in
the claims.
There is accordingly provided a printed security feature provided onto a
printable substrate, which printed security feature includes a printed area
consisting of a multiplicity of adjacent rectilinear and/or curvilinear
elements
printed with a given spatial frequency. According to the invention, the
rectilinear
and/or curvilinear elements are printed with at least first and second inks
which
exhibit the same or substantially the same optical appearance when illuminated
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
2
with visible white light, such that the printed security feature produces a
first
graphical representation when illuminated with visible white light, at least
the
first ink being an ink which responds to non-visible light excitation by
producing
a characteristic optical response differentiating the first ink from the
second ink-
The printed security feature produces a second graphical representation when
illuminated with non-visible light, which second graphical representation
exhibits
a distinctive two-dimensional graphic element which is revealed only when the
printed security feature is illuminated with non-visible light. Inside
boundaries of
the distinctive two-dimensional graphic element, a part of the rectilinear
and/or
curvilinear elements is printed with a combination of the first and second
inks,
the rectilinear and/or curvilinear elements being subdivided, within that
part, into
first and second juxtaposed sections, the first juxtaposed sections being
printed
with the first ink and the second juxtaposed sections being printed with the
second ink. Outside the boundaries of the distinctive two-dimensional graphic
element, portions of the rectilinear and/or curvilinear elements are printed
with
only one of the at least first and second inks. The at least first and second
inks
are printed in register one with respect to the other so that the boundaries
of the
distinctive two-dimensional graphic element are not visible when the printed
security feature is illuminated with visible white light and the distinctive
two-
dimensional graphic element only becomes visible when the printed security
feature is illuminated with non-visible light.
A key advantage of the present invention resides in the fact that it
requires a precise printing process in order to print the at least first and
second
inks with the adequate register, which printing process is not readily
available to
counterfeiters. A misregistration between the colours will result in the
boundaries of the distinctive two-dimensional graphic element becoming visible
under visible light, thereby revealing the presence of the two-dimensional
graphic element which is normally concealed under visible light.
The printed security feature may advantageously be such that, outside
the boundaries of the distinctive two-dimensional graphic element, a first
portion
the rectilinear and/or curvilinear elements is printed only with the first ink
and a
second portion of the rectilinear and/or curvilinear elements is printed only
with
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
3
the second ink. Preferably, the printed security feature may further be such
that,
the rectilinear and/or curvilinear elements are further printed with at least
third
and fourth inks which exhibit the same or substantially the same optical
appearance when illuminated with visible white light, which optical appearance
of the third and fourth inks is different from the optical appearance of the
first
and second inks. In this context, the third ink is an ink which responds to
non-
visible light excitation by producing a characteristic optical response
differentiating the third ink from the fourth ink, which characteristic
optical
response of the third ink is the same or substantially the same as the
characteristic optical response of the first ink. In such case, inside the
boundaries of the distinctive two-dimensional graphic element, a second part
of
the rectilinear and/or curvilinear elements is printed with a combination of
the
third and fourth inks, the rectilinear and/or curvilinear elements being
subdivided, within that second part, into first and second juxtaposed
sections,
the first juxtaposed sections being printed with the third ink and the second
juxtaposed sections being printed with the fourth ink. Outside the boundaries
of
the distinctive two-dimensional graphic element, a third portion of the
rectilinear
and/or curvilinear elements is printed only with the third ink, and a fourth
portion
of the rectilinear and/or curvilinear elements is printed only with the fourth
ink.
The third and fourth inks are likewise printed in register one with respect to
the
other so that the boundaries of the distinctive two-dimensional graphic
element
are not visible when the printed security feature is illuminated with visible
white
light and the distinctive two-dimensional graphic element only becomes visible
when the printed security feature is illuminated with non-visible light.
Preferably, the first graphical representation exhibits a first two-
dimensional graphic element which is distinguishable from the distinctive two-
dimensional graphic element that becomes visible when the printed security
feature is illuminated with non-visible light, the first two-dimensional
graphic
element and the distinctive two-dimensional graphic element being positioned
in
a partially overlapping manner within the printed area.
In one variant of this preferred embodiment (see Figures 1 to 5), the first
two-dimensional graphic element and the distinctive two-dimensional graphic
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
4
element have identical shapes (e.g. a triangular shape in the illustrated
example) and are designed in such a way that commutation between the first
two-dimensional graphic element and the distinctive two-dimensional graphic
element gives the impression of a flip or movement of a same graphic element
from one position to another (e.g. a triangular shape pointing downwards or
upwards).
In another variant of this preferred embodiment (see Figures 6 to 10), the
first two-dimensional graphic element and the distinctive two-dimensional
graphic element have different shapes each providing recognizable information
(e.g. the numerical symbols "1" and "2" in the illustrated example) and are
designed in such a way that commutation between the first two-dimensional
graphic element and the distinctive two-dimensional graphic element leads to a
recognizable change in information (e.g. a change between the numerical
symbol "1" and the numerical symbol "2").
Advantageously, the multiplicity of adjacent rectilinear and/or curvilinear
elements include a first set of rectilinear and/or curvilinear elements
extending
over a first zone of the printed area and at least a second set of rectilinear
and/or curvilinear elements extending over a second zone of the printed area,
which helps in defining a first graphical representation that can suitably be
identified in the state where the printed security feature is illuminated with
visible white light. In that context, it is preferable to design the
rectilinear and/or
curvilinear elements of the first set so that they extend along a first
orientation
and the rectilinear and/or curvilinear elements of the second set so that they
extend along a second orientation different from the first orientation.
Likewise,
the first and second sets of rectilinear and/or curvilinear elements can
advantageously be separated by an unprinted borderline.
In accordance with a particularly preferred embodiment (as discussed
hereinafter), the first ink is a first fluorescent ink which produces a
visible
response having a first fluorescent colour when subjected to the non-visible
light
excitation (preferably ultraviolet excitation), the first fluorescent colour
contributing to making the distinctive two-dimensional graphic element visible
when the printed security feature is subjected to the non-visible light
excitation.
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
According to a particularly advantageous variant of this preferred embodiment,
the second ink is a second fluorescent ink which produces a visible response
having a second fluorescent colour when subjected to the non-visible light
excitation, which second fluorescent colour is distinct from the first
fluorescent
5 colour. Accordingly, inside the boundaries of the distinctive two-
dimensional
graphic element, the first and second juxtaposed sections of the rectilinear
and/or curvilinear elements produce, when subjected to the non-visible light
excitation, a third fluorescent colour resulting from additive mixture of the
first
and second fluorescent colours.
In yet another embodiment which adopts four different inks as mentioned
above, the first ink is a first fluorescent ink which produces a visible
response
having a first fluorescent colour when subjected to the non-visible light
excitation (preferably ultraviolet excitation), the first fluorescent colour
contributing to making the distinctive two-dimensional graphic element visible
when the printed security feature is subjected to the non-visible light
excitation,
and the third ink is a fluorescent ink which produces a visible response
having
the same or substantially the same first fluorescent colour as the first
fluorescent ink when subjected to the non-visible light excitation. According
to a
particularly advantageous variant of this other embodiment, the second ink is
a
second fluorescent ink which produces a visible response having a second
fluorescent colour when subjected to the non-visible light excitation, which
second fluorescent colour is distinct from the first fluorescent colour, and
the
fourth ink is a fluorescent ink which produces a visible response having the
same or substantially the same second fluorescent colour as the second
fluorescent ink when subjected to the non-visible light excitation.
Accordingly,
inside the boundaries of the distinctive two-dimensional graphic element, the
first and second juxtaposed sections of the rectilinear and/or curvilinear
elements produce, when subjected to the non-visible light excitation, a third
fluorescent colour resulting from additive mixture of the first and second
fluorescent colours.
In accordance with the invention, the rectilinear and/or curvilinear
elements preferably exhibit a line width in the range of 20 pm to 200 pm. The
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
6
line width of the rectilinear and/or curvilinear elements can be constant, it
being
however to be appreciated that the line width of the rectilinear and/or
curvilinear
elements could be modulated so as to represent an additional piece of
information.
Preferably, the rectilinear and/or curvilinear elements are printed with a
spatial frequency of 2 to 50 lines per millimetre, which ensures homogenous
graphical representations both when the security feature is illuminated with
visible white light and when the security feature is illuminated with non-
visible
light (e.g. UV light).
A ratio of a surface of the first juxtaposed sections over a surface of the
second juxtaposed sections, inside the boundaries of the distinctive two-
dimensional graphic element, can conveniently lie within a range of 1/2 to 2,
which provides flexibility to modulate the intensity of the colour appearance
of
the distinctive two-dimensional graphic element when it is revealed as a
result
of illumination of the printed security feature with non-visible light. This
is
especially useful in order to modulate the respective contributions of first
and
second fluorescent inks discussed above (and third and fourth fluorescent inks
as the case may be), thereby allowing an adjustment of the third fluorescent
colour resulting from additive mixture of the first and second fluorescent
colours.
The multiplicity of adjacent rectilinear and/or curvilinear elements is
preferably printed by Simultan-offset, namely by inking first and second
offset
printing plates with the first and second inks, respectively, and by
transferring
resulting first and second ink patterns from the first and second offset
printing
plates onto a common blanket cylinder prior to printing. Other printing
processes could be contemplated (such as intaglio printing) provided the
printing process is adapted to print the multiplicity of adjacent rectilinear
and/or
curvilinear elements with an adequate register between the first and second
inks.
Also claimed is an object comprising a substrate and a printed security
feature in accordance with the invention, which printed security feature is
provided onto the substrate. In this context, the printed security feature is
advantageously provided on a portion of the substrate which absorbs a
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
7
substantial part of the non-visible light excitation. This portion can either
be a
portion of the substrate itself or a suitable layer applied onto the substrate
prior
to printing of the security feature. This portion ensures a better contrast
between the security feature and the background (when illuminated with non-
visible light) as the background will appear mostly dark under illumination
with
non-visible light.
The object can be a value document (in particular a high security
document such as a banknote), or a security element that is applicable onto an
article to be protected against forgery (in particular a foil element, such as
a
transferable foil element that can be transferred by e.g. hot-stamping or a
foil
element that can be laminated onto a suitable surface of the article).
Also claimed is a process of producing an object comprising a substrate
and a printed security feature, wherein the process includes providing a
printable substrate and printing the security feature in accordance with the
invention onto the substrate.
Further advantageous embodiments of the invention are discussed
below.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will appear more
clearly from reading the following detailed description of embodiments of the
invention which are presented solely by way of non-restrictive examples and
illustrated by the attached drawings in which:
Figure 1 is a schematic view of a printed security feature in accordance
with a first embodiment of the invention, Figure 1 illustrating the printed
security
feature when illuminated with visible white light ;
Figure 2 is a schematic view of the printed security feature of Figure 1
where boundaries of a distinctive two-dimensional graphic element (which
element is designated generally by reference B) are shown in dashed lines,
this
distinctive two-dimensional graphic element being revealed only when the
printed feature is illuminated with non-visible light (e.g. ultraviolet light)
;
Figures 3A and 3B are detailed views of first and second partial areas of
the printed security feature of Figure 1 showing details of the rectilinear
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
8
elements constituting the printed area of the security feature, inside and
outside
of the boundaries of the distinctive two-dimensional graphic element;
Figure 4 is a schematic illustration of the spatial distribution of first,
second and third fluorescent colours which are produced by the security
feature
of Figure 1 when subjected to non-visible light excitation, namely ultraviolet
excitation in this example ;
Figure 5 is a schematic illustration of the resulting appearance of the
printed security feature of Figure 1, when subjected to the non-visible light
(e.g.
ultraviolet) excitation ;
Figure 6 is a schematic view of a printed security feature in accordance
with a second embodiment of the invention, Figure 6 illustrating the printed
security feature when illuminated with visible white light ;
Figure 7 is a schematic view of the printed security feature of Figure 6
where boundaries of a distinctive two-dimensional graphic element (which
element is designated generally by reference D) are shown in dashed lines,
this
distinctive two-dimensional graphic element being revealed only when the
printed feature is illuminated with non-visible light (e.g. ultraviolet light)
;
Figures 8A to 8C are detailed views of first, second and third partial
areas of the printed security feature of Figure 6 showing details of the
rectilinear
elements constituting the printed area of the security feature, inside and
outside
of the boundaries of the distinctive two-dimensional graphic element;
Figure 9 is a schematic illustration of the spatial distribution of first,
second and third fluorescent colours which are produced by the security
feature
of Figure 6 when subjected to non-visible light excitation, namely ultraviolet
excitation in this example ;
Figure 10 is a schematic illustration of the resulting appearance of the
printed security feature of Figure 6, when subjected to the non-visible light
(e.g.
ultraviolet) excitation ;
Figure 11 is a schematic view of a variant of the printed security feature
of Figure 1 illustrating the printed security feature when illuminated with
visible
white light, which variant is printed using four different inks ;
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
9
Figure 12 is a schematic view of the printed security feature of Figure 11
where boundaries of a distinctive two-dimensional graphic element (which
element is designated generally by reference F) are shown in dashed lines,
this
distinctive two-dimensional graphic element being revealed only when the
printed feature is illuminated with non-visible light (e.g. ultraviolet
light), in the
same way as in the first embodiment;
Figure 13 is a schematic illustration of the resulting appearance of the
printed security feature of Figure 11, when subjected to the non-visible light
(e.g. ultraviolet) excitation, which appearance is similar to that shown in
Figure
5;
Figure 14 is a schematic view of a variant of the printed security feature
of Figure 6 illustrating the printed security feature when illuminated with
visible
white light, which variant is printed using four different inks ;
Figure 15 is a schematic view of the printed security feature of Figure 14
where boundaries of a distinctive two-dimensional graphic element (which
element is designated generally by reference H) are shown in dashed lines,
this
distinctive two-dimensional graphic element being revealed only when the
printed feature is illuminated with non-visible light (e.g. ultraviolet light)
, in the
same way as in the second embodiment ; and
Figure 16 is a schematic illustration of the resulting appearance of the
printed security feature of Figure 6, when subjected to the non-visible light
(e.g.
ultraviolet) excitation, which appearance is similar to that shown in Figure
10.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
The present invention will be described in the particular context of a
printed security feature which is printed by means of at least first and
second
fluorescent inks which produce corresponding visible responses when
subjected to non-visible light excitation, the first and second inks producing
distinct visible responses having respectively first and second fluorescent
colours which are different from one another. In the examples that will be
described hereinafter, the first fluorescent ink is an ink that fluoresces a
green
colour, while the second fluorescent ink is an ink that fluoresces a red
colour.
These examples are purely illustrative and other fluorescent colours could be
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
contemplated without departing from the scope of the invention as defined by
the claims. As this will be appreciated hereinafter, the first and second
fluorescent inks advantageously combine, in certain locations of the printed
security feature, to form a third fluorescent colour resulting from additive
mixture
5 of the first and second fluorescent colour. In the following, it will be
assumed
that each of the first and second fluorescent colours contribute equally to
the
third fluorescent colour, thereby leading to a yellow fluorescent colour in
the
examples. It will however be appreciated that the third colour will actually
be
dependent on the relevant contributions of the first and second fluorescent
10 colours in the additive mixture. The more the red contribution, the more
the third
colour will turn from yellow to orange and to red. The more the green
contribution, the more the third colour will turn to a light green and to
green.
It the present example, it will be assumed that the non-visible light
excitation is ultraviolet excitation. It is however to be appreciated that the
non-
visible light excitation could alternatively be a near-infrared excitation or
any
other excitation outside the visible spectrum that can suitably trigger a
visible
response. Within the scope of the present invention, only one or more than two
inks responsive to the non-visible light excitation could be contemplated.
Figures 1 to 5 show a printed security feature (generally identified by
reference numeral 1) in accordance with a first embodiment of the invention,
which printed security feature 1 is characterized by the fact that the first
graphical representation of the printed security feature (under visible light)
exhibits a first two-dimensional graphic element A (namely a triangular shape
pointing downwards ¨ see Figures 1 to 3A-3B) which is distinguishable from the
distinctive two-dimensional graphic element B (namely a triangular shape
pointing upwards ¨ see Figures 2 to 5) that becomes visible when the printed
security feature is illuminated with non-visible light, the first two-
dimensional
graphic element A and the distinctive two-dimensional graphic element B being
positioned in a partially overlapping manner within the printed area of the
security feature 1 (see Figure 2), which printed area is designated by
reference
numeral 100 in Figures 1 to 5. Boundaries of the distinctive two-dimensional
graphic element B are depicted by dashed lines in Figures 2 to 5 and are
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
11
designated by reference numeral 160. In the example of Figures 1 to 5, the
first
two-dimensional graphic element A and the distinctive two-dimensional graphic
element B have identical shapes (i.e. a triangular shape in the illustrated
example) and are designed in such a way that commutation between the first
two-dimensional graphic element A and the distinctive two-dimensional graphic
element B gives the impression of a flip or movement of a same graphic
element from one position to another (namely a triangular shape pointing
downwards or upwards).
In contrast, Figures 6 to 10 show a printed security feature (generally
identified by reference numeral 1*) in accordance with a second embodiment of
the invention, which printed security feature 1* is characterized by the fact
that
the first graphical representation of the printed security feature (under
visible
light) exhibits a first two-dimensional graphic element C (namely the
numerical
symbol "1" ¨ see Figures 6 to 8A-8C) which is distinguishable from the
distinctive two-dimensional graphic element D (namely the numerical symbol "2"
¨ see Figures 7 to 10) that becomes visible when the printed security feature
is
illuminated with non-visible light, the first two-dimensional graphic element
C
and the distinctive two-dimensional graphic element D being positioned in a
partially overlapping manner within the printed area of the security feature
1*
(see Figure 7), which printed area is designated by reference numeral 200 in
Figures 6 to 10. Boundaries of the distinctive two-dimensional graphic element
D are depicted by dashed lines in Figures 7 to 10 and are designated by
reference numeral 260. In the example of Figures 6 to 10, the first two-
dimensional graphic element C and the distinctive two-dimensional graphic
element D have different shapes each providing recognizable information (i.e.
the numerical symbols "1" and "2" in the illustrated example) and are designed
in such a way that commutation between the first two-dimensional graphic
element C and the distinctive two-dimensional graphic element D leads to a
recognizable change in information (namely a change between the numerical
symbol "1" and the numerical symbol "2").
In both embodiments, the printed area 100, respectively 200, consists of
a multiplicity of parallel rectilinear elements designated by reference
numerals
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
12
110, 120 in Figures 1 to 5 and by reference numerals 210, 220 in Figures 6 to
10. These rectilinear elements 110, 120, respectively 210, 220, are printed
with
a given spatial frequency which is preferably of the order of 2 to 50 lines
per
millimetre. While the Figures show rectilinear elements 110, 120, respectively
210, 220, the invention is equally applicable to security features including a
printed area consisting of a multiplicity of adjacent curvilinear elements
(such as
adjacent waves, concentric circles, or any other non rectilinear elements that
can be printed in the way of a multiplicity of adjacent elements).
Combinations
of rectilinear and curvilinear elements are also possible.
Preferably, the multiplicity of parallel rectilinear elements 110, 120 of
Figures 1 to 5, include a first set of rectilinear elements 110 extending over
a
first zone 101 of the printed area 100 and at least a second set of
rectilinear
elements 120 extending over a second zone 102 of the printed area 100.
Likewise, the multiplicity of parallel rectilinear elements 210, 220 of
Figures 6 to
10, include a first set of rectilinear elements 210 extending over a first
zone 201
of the printed area 200 and at least a second set of rectilinear elements 220
extending over a second zone 202 of the printed area 200. This helps in
defining a first graphical representation that can suitably be identified in
the
state where the printed security feature is illuminated with visible white
light.
In that context, it is preferable to design the rectilinear elements of the
first set 110, respectively 210, so that they extend along a first orientation
(namely vertically in the examples) and the rectilinear elements of the second
set 120, respectively 220, so that they extend along a second orientation
different from the first orientation (namely horizontally in the illustrated
examples). In addition, in the illustrations of Figures 1 to 10, the first and
second
sets 110, 120, respectively 210, 220 of rectilinear elements are separated by
an
unprinted borderline designated by reference numeral 150 in Figures 1 to 5 and
by reference numeral 250 in Figures 6 to 10.
In the illustrated examples, the elements 110, 120, respectively 210, 220,
preferably have a constant line width w, which line width w can conveniently
be
selected to be in the range of 20 pm to 200 pm. Within the scope of the
present
invention, a modulation of the line width can however be contemplated so as to
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
13
represent an additional piece of information. In the illustrated examples, it
will
be assumed that the elements 110, 120, respectively 210, 220, have a line
width of the order of 100 pm and that the spatial frequency of the elements
110,
120, respectively 210, 220, is of the order of 5 lines per millimetres. The
unprinted borderline 150, respectively 250, exhibits a width of the order of
150 pm in the illustrated examples.
In accordance with the invention, the rectilinear elements 110, 120,
respectively 210, 220, are printed with at least first and second inks which
exhibit the same or substantially the same optical appearance when illuminated
with visible white light, such that the printed security feature 1,
respectively 1*,
produces a first graphical representation (Figure 1, Figure 6) when
illuminated
with visible white light. As already mentioned, the first and second inks are
preferably first and second fluorescent inks having distinctive fluorescent
colours (namely green and red in this example).
Referring to Figures 3A and 3B, one can see that, inside the boundaries
160 of the two-dimensional graphic element B, the rectilinear elements 110,
120
are subdivided into first and second juxtaposed sections 110a, 110b (see
Figure
3A), respectively 120a, 120b (see Figure 3B). In other words, the first and
second juxtaposed sections 110a, 110b, respectively 120a, 120b, are printed so
as to join one with the other and be contiguous. The first juxtaposed sections
110a, 120a are printed with the first fluorescent ink (i.e. the fluorescent
green
ink - identified by hatchings in Figures 3A and 3B), while the second
juxtaposed
sections 110b, 120b are printed with the second ink (i.e. the fluorescent red
ink
- identified by a solid colour in Figures 3A and 3B). Outside the boundaries
160
of the two-dimensional graphic element B, the rectilinear elements 110, 120
are
printed with only the first ink (see e.g. Figure 3B) or the second ink (see
e.g.
Figure 3A).
Similarly, referring to Figures 8A to 8C, one can see that, inside the
boundaries 260 of the two-dimensional graphic element D, the rectilinear
elements 210, 220 are subdivided into first and second juxtaposed sections
210a, 210b (see Figure 8A), respectively 220a, 220b (see Figures 8B and 8C).
In other words, the first and second juxtaposed sections 210a, 210b,
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
14
respectively 220a, 220b, are printed so as to join one with the other and be
contiguous. The first juxtaposed sections 210a, 220a are printed with the
first
fluorescent ink (i.e. the fluorescent green ink ¨ identified by hatchings in
Figures
8A to 8C), while the second juxtaposed sections 210b, 220b are printed with
the
second ink (i.e. the fluorescent red ink ¨ identified by a solid colour in
Figures
8A to 8C). Outside the boundaries 260 of the two-dimensional graphic element
D, the rectilinear elements 210, 220 are printed with only the first ink (see
e.g.
Figures 8A and 8B) or the second ink (see e.g. Figure 8C).
In both instances, the first and second inks are printed in register one
with respect to the other so that the boundaries 160, respectively 260, of the
two-dimensional graphic element B, respectively D, are not visible when the
printed security feature is illuminated with visible white light and the two-
dimensional graphic element B, respectively D, only becomes visible when the
printed security feature is illuminated with non-visible light.
Indeed, as illustrated by Figure 4, the arrangement of the first and
second inks is such that, when the security feature 1 is subjected to
ultraviolet
excitation, the portion P1 of the rectilinear elements 110, 120, outside the
boundaries 160 of the two-dimensional graphic element B, that is entirely
printed with the first ink appears as a fluorescent green region (triangular
area
at the upper-left corner of the printed area 100 in Figure 4) while the
portion P2
of the rectilinear elements 110, 120, outside the boundaries 160 of the two-
dimensional graphic element B, that is entirely printed with the second ink
appears as a fluorescent red region (triangular area at the upper-right corner
of
the printed area 100 in Figure 4). The remaining portion P3 of the rectilinear
elements 110, 120, inside the boundaries 160 of the two-dimensional graphic
element B (i.e. the portion forming the triangular shape pointing upwards),
that
is printed with a combination of the first and second fluorescent inks appears
as
a fluorescent yellow region thanks to the additive mixture of the fluorescent
green and red colours.
The same is true in respect of the embodiment of Figures 6 to 10.
Indeed, as illustrated by Figure 9, the arrangement of the first and second
inks
is such that, when the security feature 1* is subjected to ultraviolet
excitation,
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
the portion P1* of the rectilinear elements 210, 220, outside the boundaries
260
of the two-dimensional graphic element D, that is entirely printed with the
first
ink appears as a fluorescent green region (portion of the background on the
left-
hand side of the numerical symbol "2" in Figure 9) while the portion P2* of
the
5 rectilinear elements 210, 220, outside the boundaries 260 of the two-
dimensional graphic element D, that is entirely printed with the second ink
appears as a fluorescent red region (portion of the background on the right-
hand side of the numerical symbol "2" in Figure 9). The remaining portion P3*
of
the rectilinear elements 210, 220, inside the boundaries 260 of the two-
10 dimensional graphic element D (i.e. the portion forming the numerical
symbol
"2"), that is printed with a combination of the first and second fluorescent
inks
appears as a fluorescent yellow region thanks to the additive mixture of the
fluorescent green and red colours.
Figures 5 and 10 are schematic illustrations showing the resulting
15 graphical representation when the printed security feature 1,
respectively 1*, is
illuminated with non-visible light (i.e. ultraviolet light).
In the aforementioned embodiments, a ratio of a surface of the first
juxtaposed sections 110a, 120a, respectively 210a, 220a, over a surface of the
second juxtaposed sections 110b, 120b, respectively 210b, 220b, inside the
boundaries 160, respectively 260, of the two-dimensional graphic element B,
respectively D, is substantially equal to 1. In other words, in the
illustrations of
Figures 3A-3B and 8A-8C, the line width of each juxtaposed section is
approximately half (i.e. w/2) that of the overall line width w of the
rectilinear
elements. This ratio can be changed if required. This ratio preferably lies
within
a range of 1/2 to 2, which provides flexibility to modulate the respective
contributions of the first and second fluorescent inks used in the
aforementioned
preferred embodiments, thereby allowing an adjustment of the third fluorescent
colour resulting from additive mixture of the first and second fluorescent
colours.
Printing of the adjacent rectilinear (and/or curvilinear elements as the
case may be) is preferably carried out by Simultan-offset, namely by inking
first
and second offset printing plates with the first and second inks,
respectively,
and by transferring the resulting first and second ink patterns from the first
and
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
16
second offset printing plates onto a common blanket cylinder prior to
printing.
Other printing processes could be contemplated (such as intaglio printing)
provided the printing process is adapted to print the multiplicity of adjacent
rectilinear and/or curvilinear elements with an adequate register between the
first and second inks. A suitable Simultan-offset printing press is for
instance
disclosed in European Patent Publication No. EP 0 949 069 Al, which is
incorporated herein by reference. The aforementioned security features 1,
respectively 1*, can conveniently be printed on one or the other side of a
sheet
(or any other suitable substrate) using two of the four plate cylinders that
cooperate with one or the other blanket cylinder of the main printing group of
the printing press of EP 0 949 069 Al (see Figure 1 thereof where reference
numerals 4 to 7, respectively 8 to 11, designate relevant plate cylinders
cooperating with a common blanket cylinder 2, respectively 3). Alternatively,
the
aforementioned security features 1, respectively 1*, could also be printed on
one side of the sheet using the two plate cylinders that cooperate with the
blanket cylinder of the additional printing group of the printing press of
EP 0 949 069 Al (see Figure 1 thereof where reference numerals 23 and 24
designate relevant plate cylinders cooperating with a common blanket cylinder
22).
Variants of the aforementioned embodiments are possible. One could in
particular contemplate to further print the rectilinear and/or curvilinear
elements
with at least third and fourth inks (in addition to the first and second
inks), which
third and fourth inks exhibit the same or substantially the same optical
appearance when illuminated with visible white light, which optical appearance
of the third and fourth inks is different from the optical appearance of the
first
and second inks. In this context, the third ink is an ink which also responds
to
non-visible light excitation by producing a characteristic optical response
differentiating the third ink from the fourth ink, which characteristic
optical
response of the third ink is the same or substantially the same as the
characteristic optical response of the first ink. Like the first and second
inks, the
third and fourth inks are also printed in register one with respect to the
other so
that the boundaries of the distinctive two-dimensional graphic element remain
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
17
invisible when the printed security feature is illuminated with visible white
light
and the distinctive two-dimensional graphic element only becomes visible when
the printed security feature is illuminated with non-visible light.
Illustrative examples of such variants are shown in Figures 11 to 13 and
14 to 16 and are briefly discussed hereinafter.
Figures 11 to 13 illustrate a variant of the first embodiment of Figures 1 to
5, where the printed security feature, designated by reference numeral 1**, is
printed using four inks as generally defined above. In this particular
example,
first and second inks are used which have the same properties as in the first
embodiment, namely first and second fluorescent inks which produce
corresponding visible responses when subjected to non-visible light
excitation,
the first and second inks producing distinct visible responses having
respectively first and second fluorescent colours which are different from one
another. Like in the first embodiment, the first fluorescent ink is an ink
that
fluoresces a green colour, while the second fluorescent ink is an ink that
fluoresces a red colour. These examples are again purely illustrative and
other
fluorescent colours could be contemplated without departing from the scope of
the invention as defined by the claims. In this example also, the first and
second
inks exhibit the same or substantially the same optical appearance when
illuminated with visible white light.
In contrast to the first embodiment, third and fourth inks are further used
to print the security feature 1**, namely third and fourth inks that exhibit
the
same or substantially the same optical appearance, but which is different from
the optical appearance of the first and second inks. In this particular
example,
the third and fourth inks are also preferably third and fourth fluorescent
inks
which produce corresponding visible responses when subjected to non-visible
light excitation, the third and fourth inks producing distinct visible
responses.
The fluorescent colour produced by the third fluorescent ink is selected to be
the same or substantially the same as the first fluorescent colour of the
first
fluorescent ink (i.e. a green colour in this case). In contrast, the
fluorescent
colour produced by the fourth fluorescent ink is selected to be the same or
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
18
substantially the same as the second fluorescent colour of the second
fluorescent ink (i.e. a red colour in this case).
Much like in the first embodiment of Figures 1 to 5, the printed security
feature 1** of Figures 11 to 13 is characterized by the fact that the first
graphical
representation of the printed security feature (under visible light) exhibits
a first
two-dimensional graphic element E (namely a triangular shape pointing
downwards) which is distinguishable from the distinctive two-dimensional
graphic element F (namely a triangular shape pointing upwards) that becomes
visible when the printed security feature is illuminated with non-visible
light, the
first two-dimensional graphic element E and the distinctive two-dimensional
graphic element F being positioned in a partially overlapping manner within
the
printed area of the security feature 1** (see Figure 12), which printed area
is
designated by reference numeral 300 in Figures 11 to 13. Boundaries of the
distinctive two-dimensional graphic element F are depicted by dashed lines in
Figures 12 and 13 and are designated by reference numeral 360. In the
example of Figures 11 to 13, the first two-dimensional graphic element E and
the distinctive two-dimensional graphic element F likewise have identical
shapes (i.e. a triangular shape in the illustrated example) and are designed
in
such a way that commutation between the first two-dimensional graphic
element E and the distinctive two-dimensional graphic element F gives the
impression of a flip or movement of a same graphic element from one position
to another (namely a triangular shape pointing downwards or upwards).
In this variant, the printed area 300 consists of a multiplicity of parallel
rectilinear elements designated by reference numerals 310, 320 in Figures 11
and 12. The geometrical and spatial arrangement of the rectilinear elements
310, 320 is identical to that of the rectilinear elements 110, 120 of the
first
embodiment. In other words, the multiplicity of parallel rectilinear elements
310,
320 include a first set of rectilinear elements 310 extending over a first
zone 301
of the printed area 300 and at least a second set of rectilinear elements 320
extending over a second zone 302 of the printed area 300. The first and second
sets 310, 320 of rectilinear elements are likewise separated by an unprinted
borderline designated by reference numeral 350, but this borderline 350 could
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
19
be omitted. The orientations of the rectilinear elements 310, 320 are the same
as that of the rectilinear elements 110, 120 of the first embodiment, but this
is
not essential.
In contrast to the first embodiment, the first graphical representation E is
enhanced by the use of inks having different optical appearances when
illuminated by visible light, namely the first and second inks, on the one
hand,
and the third and fourth inks, on the other hand. More precisely, the first
zone
301 consists of rectilinear elements 310 that are printed using the first and
second inks, while the second zone 302 consists of rectilinear elements 320
that are printed using the third and fourth inks. The first and second zones
301,
302 are therefore clearly differentiable due to the different optical
appearances
of the first and second inks compared to the third and fourth inks.
The portion P3** of the rectilinear elements 310, within the boundaries
360 of the distinctive two-dimensional graphic element F, is printed with a
combination of the first and second inks like in the first embodiment.
Similarly,
the portions P1**, P2** of the rectilinear elements 310, outside the
boundaries
360 of the distinctive two-dimensional graphic element F, are printed with
either
the first or the second ink. By the same token, the two portions P6** of the
rectilinear elements 320, within the boundaries 360 of the distinctive two-
dimensional graphic element F, are printed with a combination of the third and
fourth inks. Similarly, the portions P4**, P5** of the rectilinear elements
320,
outside the boundaries 360 of the distinctive two-dimensional graphic element
F, are printed with either the third or fourth ink.
The rectilinear elements 310, 320 are printed, inside the boundaries 360,
along the same principle as already described with reference to Figure 3A and
3B, with the difference that the rectilinear elements 310 are subdivided (in
portion P3**) into first and second juxtaposed sections which are printed with
a
combination of the first and second inks, while the rectilinear elements 320
are
subdivided (in portion P6**) into first and second juxtaposed sections which
are
printed with a combination of the third and fourth inks. The same rules as
described above in connection with the previous embodiments apply, including
the comments regarding line width w and line frequency.
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
In this example, the triangular portion of the rectilinear elements 320 on
the left-hand side of the printed area 300, outside of the boundaries 360,
(i.e.
portion P4**) is printed exclusively with the third ink, such as to jointly
form,
together with the triangular portion P1** of the rectilinear elements 310
which is
5 printed
exclusively with the first ink, a triangular portion that fluoresces in green
colour when illuminated with non-visible light (i.e. ultraviolet light) like
in the
embodiment of Figures 1 to 5. Likewise, the triangular portion P5** of the
rectilinear elements 320 on the right-hand side of the printed area 300 is
printed
exclusively with the fourth ink, such as to jointly form, together with the
10 triangular portion P2** of the rectilinear elements 310 which is printed
exclusively with the second ink, a triangular portion that fluoresces in red
colour
when illuminated with non-visible light (i.e. ultraviolet light) like in the
embodiment of Figures 1 to 5.
Within the boundaries 360 of the distinctive two-dimensional graphic
15 element
F, the combination of the first and second inks (in portion P3**), on the
one hand, and the combination of third and fourth inks (in portions P6**), on
the
other hand, both lead to the formation a readily recognizable triangular
element
F that fluoresces in yellow colour due to the additive mixture of the
fluorescent
green and red colours.
20 Figures
14 to 16 illustrate a variant of the second embodiment of Figures
6 to 10, where the printed security feature, designated by reference numeral
1***, is printed using four inks as generally defined above. In this
particular
example, first and second inks are used which have the same properties as in
the second embodiment, namely first and second fluorescent inks which
produce corresponding visible responses when subjected to non-visible light
excitation, the first and second inks producing distinct visible responses
having
respectively first and second fluorescent colours which are different from one
another. Like in the second embodiment, the first fluorescent ink is an ink
that
fluoresces a green colour, while the second fluorescent ink is an ink that
fluoresces a red colour. These examples are once again purely illustrative and
other fluorescent colours could be contemplated without departing from the
scope of the invention as defined by the claims. In this example also, the
first
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
21
and second inks exhibit the same or substantially the same optical appearance
when illuminated with visible white light.
In contrast to the second embodiment, third and fourth inks are further
used to print the security feature 1***, namely third and fourth inks that
exhibit
the same or substantially the same optical appearance, but which is different
from the optical appearance of the first and second inks. In this particular
example, the third and fourth inks are also preferably third and fourth
fluorescent inks which produce corresponding visible responses when
subjected to non-visible light excitation, the third and fourth inks producing
distinct visible responses. The fluorescent colour produced by the third
fluorescent ink is again selected to be the same or substantially the same as
the
first fluorescent colour of the first fluorescent ink (i.e. a green colour in
this
case). Likewise, the fluorescent colour produced by the fourth fluorescent ink
is
again selected to be the same or substantially the same as the second
fluorescent colour of the second fluorescent ink (i.e. a red colour in this
case).
Much like in the second embodiment of Figures 6 to 10, the printed
security feature 1*** of Figures 14 to 16 is characterized by the fact that
the first
graphical representation of the printed security feature (under visible light)
exhibits a first two-dimensional graphic element G (namely the numerical
symbol "1") which is distinguishable from the distinctive two-dimensional
graphic
element H (namely the numerical symbol "2") that becomes visible when the
printed security feature is illuminated with non-visible light, the first two-
dimensional graphic element G and the distinctive two-dimensional graphic
element H being positioned in a partially overlapping manner within the
printed
area of the security feature 1*** (see Figure 15), which printed area is
designated by reference numeral 400 in Figures 14 to 16. Boundaries of the
distinctive two-dimensional graphic element H are depicted by dashed lines in
Figures 15 and 16 and are designated by reference numeral 460. In the
example of Figures 14 to 16, the first two-dimensional graphic element G and
the distinctive two-dimensional graphic element H likewise have different
shapes each providing recognizable information (i.e. the numerical symbols "1"
and "2" in the illustrated example) and are designed in such a way that
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
22
commutation between the first two-dimensional graphic element G and the
distinctive two-dimensional graphic element H leads to a recognizable change
in information (namely a change between the numerical symbol "1" and the
numerical symbol "2").
In this variant, the printed area 400 consists of a multiplicity of parallel
rectilinear elements designated by reference numerals 410, 420 in Figures 14
and 15. The geometrical and spatial arrangement of the rectilinear elements
410, 420 is identical to that of the rectilinear elements 210, 220 of the
second
embodiment. In other words, the multiplicity of parallel rectilinear elements
410,
420 include a first set of rectilinear elements 410 extending over a first
zone 401
of the printed area 400 and at least a second set of rectilinear elements 420
extending over a second zone 402 of the printed area 400. The first and second
sets 410, 420 of rectilinear elements are likewise separated by an unprinted
borderline designated by reference numeral 450, but this borderline 450 could
be omitted. The orientations of the rectilinear elements 410, 420 are the same
as that of the rectilinear elements 210, 220 of the first embodiment, but this
is
again not essential.
In contrast to the second embodiment, the first graphical representation
G is enhanced by the use of inks having different optical appearances when
illuminated by visible light, namely the first and second inks, on the one
hand,
and the third and fourth inks, on the other hand. More precisely, the first
zone
401 consists of rectilinear elements 410 that are printed using the first and
second inks, while the second zone 402 consists of rectilinear elements 420
that are printed using the third and fourth inks. The first and second zones
401,
402 are therefore clearly differentiable due to the different optical
appearances
of the first and second inks compared to the third and fourth inks.
The portion P3*** of the rectilinear elements 410, within the boundaries
460 of the distinctive two-dimensional graphic element H, is printed with a
combination of the first and second inks like in the first embodiment.
Similarly,
the portions P1***, P2*** of the rectilinear elements 410, outside the
boundaries
460 of the distinctive two-dimensional graphic element H, are printed with
either
the first or the second ink (note that, in the illustrated example, there are
two
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
23
further portions of the rectilinear elements 410 above the graphic element H).
By the same token, the portions P6*** of the rectilinear elements 420, within
the
boundaries 460 of the distinctive two-dimensional graphic element H, are
printed with a combination of the third and fourth inks. Similarly, the
portions
P4***, P5*** of the rectilinear elements 420, outside the boundaries 460 of
the
distinctive two-dimensional graphic element F, are printed with either the
third or
fourth ink.
The rectilinear elements 410, 420 are printed, inside the boundaries 460,
along the same principle as already described with reference to Figure 8A to
8C, with the difference that the rectilinear elements 410 are subdivided into
first
and second juxtaposed sections which are printed with a combination of the
first
and second inks, while the rectilinear elements 420 are subdivided into first
and
second juxtaposed sections which are printed with a combination of the third
and fourth inks. Once again, the same rules as described above in connection
with the previous embodiments apply, including the comments regarding line
width w and line frequency..
In this example, the portions of the rectilinear elements 420 on the left-
hand side of the printed area 400, outside of the boundaries 460, (i.e.
portions
P4***) are printed exclusively with the third ink, such as to jointly form,
together
with the corresponding portions P1*** of the rectilinear elements 410 which
are
printed exclusively with the first ink, a left portion that fluoresces in
green colour
when illuminated with non-visible light (i.e. ultraviolet light) like in the
embodiment of Figures 6 to 10. Likewise, the portion P5*** of the rectilinear
elements 420 on the right-hand side of the printed area 400, outside of the
boundaries 460, is printed exclusively with the fourth ink, such as to jointly
form,
together with the corresponding portions P2*** of the rectilinear elements 410
which are printed exclusively with the second ink, a right portion that
fluoresces
in red colour when illuminated with non-visible light (i.e. ultraviolet light)
like in
the embodiment of Figures 6 to 10.
Within the boundaries 460 of the distinctive two-dimensional graphic
element H, the combination of the first and second inks (in portion P3***), on
the
one hand, and the combination of third and fourth inks (in portions P6***), on
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
24
the other hand, both lead to the formation a readily recognizable element H
forming the numerical symbol "2" that fluoresces in yellow colour due to the
additive mixture of the fluorescent green and red colours.
Various modifications and/or improvements may be made to the above-
described embodiments without departing from the scope of the invention as
defined by the annexed claims.
As already mentioned, within the scope of the present invention, the
printed area can consist of a multiplicity of adjacent rectilinear and/or
curvilinear
elements printed with a given spatial frequency. The invention is not
therefore
limited to the illustrated examples where the printed area only consists of a
multiplicity of adjacent rectilinear elements 110, 120, respectively 210, 220.
In addition, the juxtaposed sections could be adjacent line sections split
along the width of the rectilinear and/or curvilinear elements as illustrated
in
Figures 3A-3B or 8A-8C or be a succession of adjacent line sections split
along
the length of the rectilinear and/or curvilinear elements.
In the above described embodiments, all the inks are fluorescent inks. It
is however to be appreciated that only one fluorescent ink could be used (as
the
first ink or second ink) in the context of the embodiments of Figures 1 to 10.
Likewise, it is to be appreciated that only two fluorescent inks producing the
same or substantially the same fluorescent colour could be used (as the first
and third inks or as the second and fourth inks) in the context of the
embodiments of Figures 11 to 16. Furthermore, the fluorescent ink(s) may be
responsive to any suitable non-visible light excitation, such as ultraviolet
excitation, near-infrared excitation, or any other suitable excitation outside
of the
visible spectrum.
LIST OF REFERENCE NUMERALS USED THEREIN
1 printed security feature (first embodiment ¨ Figures 1 to 5)
100 printed area (first embodiment)
101 first zone of printed area 100 / triangular area pointing downward from
the upper edge of printed area 100 in Figure 1
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
102 second zone of printed area 100 / triangular areas located on each
side
of the triangular area 101 in Figure 1
A (first) two-dimensional graphic element (e.g. triangular shape
pointing
downwards) visible when the printed security feature 1 is illuminated
5 with visible white light (Figure 1)
B (second) distinctive two-dimensional graphic element (e.g.
triangular
shape pointing upwards) which becomes visible when the printed
security feature 1 is illuminated with non-visible light (Figures 4, 5)
110 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
10 elements extending over first zone 101 / lines extending along a first
(e.g. vertical) orientation
110a first (juxtaposed) section of rectilinear elements 110, inside the
boundaries 160 of the distinctive two-dimensional graphic element B,
which is printed with a first ink that is responsive to non-visible light
15 excitation by producing a characteristic optical response / e.g.
(first)
fluorescent ink producing a (first) fluorescent (e.g. green) colour when
subjected to the non-visible light excitation (e.g. ultraviolet excitation)
110b second (juxtaposed) section of rectilinear elements 110, inside the
boundaries 160 of the distinctive two-dimensional graphic element B,
20 which is printed with a second ink / e.g. (second) fluorescent ink
producing a (second) fluorescent (e.g. red) colour when subjected to
the non-visible light excitation (e.g. ultraviolet excitation)
120 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over second zone 102 / lines extending along a
25 second (e.g. horizontal) orientation
120a first (juxtaposed) section of rectilinear elements 120, inside the
boundaries 160 of the distinctive two-dimensional graphic element B,
which is printed with the first ink (same ink as 110a)
120b second (juxtaposed) section of rectilinear elements 120, inside the
boundaries 160 of the distinctive two-dimensional graphic element B,
which is printed with the second ink (same ink as 110b)
150 unprinted borderline between first and second zones 101, 102
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
26
160 boundaries of two-dimensional graphic element B (not visible when
illuminated with visible white light)
P1 portion(s) of elements 110, 120 printed exclusively with the first
(fluorescent) ink
P2 portion(s) of elements 110, 120 printed exclusively with the second
(fluorescent) ink
P3 portion(s) of elements 110, 120 printed with a combination of the
first
and second (fluorescent) inks
1* printed security feature (second embodiment ¨ Figures 6 to 10)
200 printed area (second embodiment)
201 first zone of printed area 200 / area forming numerical symbol "1"
in
Figure 6
202 second zone of printed area 200 / background area surrounding the
numerical symbol "1" in Figure 6
C (first) two-dimensional graphic element (e.g. numerical symbol "1")
visible when the printed security feature 1* is illuminated with visible
white light (Figure 6)
D (second) distinctive two-dimensional graphic element (e.g.
numerical
symbol "2") which becomes visible when the printed security feature 1*
is illuminated with non-visible light (Figures 9, 10)
210 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over first zone 201 / lines extending along a first
(e.g. vertical) orientation
210a first (juxtaposed) section of rectilinear elements 210, inside the
boundaries 260 of the distinctive two-dimensional graphic element D,
which is printed with a first ink that is responsive to non-visible light
excitation by producing a characteristic optical response / e.g. (first)
fluorescent ink producing a (first) fluorescent (e.g. green) colour when
subjected to the non-visible light excitation (e.g. ultraviolet excitation)
210b second (juxtaposed) section of rectilinear elements 210, inside the
boundaries 260 of the distinctive two-dimensional graphic element D,
which is printed with a second ink / e.g. (second) fluorescent ink
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
27
producing a (second) fluorescent (e.g. red) colour when subjected to
the non-visible light excitation (e.g. ultraviolet excitation)
220 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over second zone 202 / lines extending along a
second (e.g. horizontal) orientation
220a first (juxtaposed) section of rectilinear elements 220, inside the
boundaries 260 of the distinctive two-dimensional graphic element D,
which is printed with the first ink (same ink as 210a)
220b second (juxtaposed) section of rectilinear elements 120, inside the
boundaries 260 of the distinctive two-dimensional graphic element D,
which is printed with the second ink (same ink as 210b)
250 unprinted borderline between first and second zones 201, 202
260 boundaries of two-dimensional graphic element D (not visible when
illuminated with visible white light)
P1* portion(s) of elements 210, 220 printed exclusively with the first
(fluorescent) ink
P2* portion(s) of elements 210, 220 printed exclusively with the second
(fluorescent) ink
P3* portion(s) of elements 210, 220 printed with a combination of the
first
and second (fluorescent) inks
w line width of rectilinear elements 110, 120, 210, 220 / combined
line
width of first and second juxtaposed sections 110a+110b, 120a+120b,
210a+210b, and 220a+220b
1** printed security feature (variant of first embodiment ¨ Figures 11-
13)
300 printed area (variant of first embodiment)
301 first zone of printed area 300 / triangular area pointing downward
from
the upper edge of printed area 300 in Figure 11
302 second zone of printed area 300 / triangular areas located on each
side
of the triangular area 301 in Figure 11
E (first) two-dimensional graphic element (e.g. triangular shape pointing
downwards) visible when the printed security feature 1** is illuminated
with visible white light (Figure 11)
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
28
F (second) distinctive two-dimensional graphic element (e.g.
triangular
shape pointing upwards) which becomes visible when the printed
security feature 1** is illuminated with non-visible light (Figure 13)
310 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over first zone 301 / lines extending along a first
(e.g. vertical) orientation
320 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over second zone 302 / lines extending along a
second (e.g. horizontal) orientation
350 unprinted borderline between first and second zones 301, 302
360 boundaries of two-dimensional graphic element F (not visible when
illuminated with visible white light)
P1** portion(s) of elements 310 printed exclusively with the first
(fluorescent)
ink
P2** portion(s) of elements 310 printed exclusively with the second
(fluorescent) ink
P3** portion(s) of elements 310 printed with a combination of the first
and
second (fluorescent) inks
P4** portion(s) of elements 320 printed exclusively with the third
(fluorescent)
ink
P5** portion(s) of elements 320 printed exclusively with the fourth
(fluorescent) ink
P6** portion(s) of elements 320 printed with a combination of the third
and
fourth (fluorescent) inks
1*** printed security feature (variant of second embodiment ¨ Figures 14-
16)
400 printed area (variant of second embodiment)
401 first zone of printed area 400 / area forming numerical symbol "1"
in
Figure 14
402 second zone of printed area 400 / background area surrounding the
numerical symbol "1" in Figure 14
CA 02911866 2015-11-06
WO 2014/184738
PCT/1B2014/061405
29
G (first) two-dimensional graphic element (e.g. numerical symbol "1")
visible when the printed security feature 1*** is illuminated with visible
white light (Figure 11)
H (second) distinctive two-dimensional graphic element (e.g.
numerical
symbol "2") which becomes visible when the printed security feature
1*** is illuminated with non-visible light (Figure 16)
410 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over first zone 401 / lines extending along a first
(e.g. vertical) orientation
420 adjacent rectilinear (and/or curvilinear) elements / parallel
rectilinear
elements extending over second zone 402 / lines extending along a
second (e.g. horizontal) orientation
450 unprinted borderline between first and second zones 401, 402
460 boundaries of two-dimensional graphic element H (not visible when
illuminated with visible white light)
P1*** portion(s) of elements 410 printed exclusively with the first
(fluorescent)
ink
P2*** portion(s) of elements 410 printed exclusively with the second
(fluorescent) ink
P3*** portion(s) of elements 410 printed with a combination of the first and
second (fluorescent) inks
P4*** portion(s) of elements 420 printed exclusively with the third
(fluorescent)
ink
P5*** portion(s) of elements 420 printed exclusively with the fourth
(fluorescent) ink
P6** portion(s) of elements 420 printed with a combination of the third
and
fourth (fluorescent) inks
